I will spread egg shells around tomato plants for calcium supply. I'm not sure it works instantly though.
It won't work instantly. I have read that the eggshell powder should be placed in the ground. If you're using it in pots, then put a layer of soil in the pot, then the eggshell powder, then more soil and the seedling. I suppose the same principle should be applied outside as well.
Those black spots on the tomatoes are not looking good and are reason for concern.
Thank you for sharing the tip @erikah. So it might be for next year ;)
I wish the following ones grow successfully without the black bottom 🍅
You're welcome. Next year you can definitely use the eggshells to help your plants. I'm doing that too, collecting eggshells till then 😃